A typical motor vehicle clutch system and assembly includes a spring biased clutch pedal, a hydraulic release system or mechanical release system and a pivotally mounted bifurcated clutch fork provided with fork clips and spring clips engaged with a clutch release (throwout) bearing. The release bearing is selectably movable along a guide member, which can for example include a support tube and/or a quill, through which a rotatable transmission input shaft of a vehicle transmission extends. The input shaft projects through and is drivingly engaged with a rotatable flywheel and a clutch unit formed from a rotatable clutch disk and a rotatable pressure plate held in a clutch cover.
When a clutch system is engaged, the clutch disk is clamped against the flywheel and transfers power from the engine crankshaft to the transmission input shaft so as to create movement of the wheels when the motor vehicle is in a particular gear setting.
When it is desired to change gears in a manual transmission, the clutch pedal is depressed to actuate the master cylinder forcing fluid therefrom and into the slave cylinder which, in turn, causes movement of a slave cylinder rod against one end of the clutch fork of opposite to an end engaged with the release bearing. The clutch fork pivots and slides the release bearing along the guide member and into engagement with the diaphragm springs or release fingers of the pressure plate. Such engagement between the release bearing and the pressure plate removes pressure from the clutch disk allowing release to occur between the clutch disk and the friction surface of the flywheel. At this point, no power is transferred to the transmission and gear changes can be made. When the clutch system is reengaged, such as after a shift, the force from the diaphragm spring supplies enough force to reverse the disengagement process and raise the clutch pedal off the floor.
Through research and experimentation, the inventors of the present disclosure have discovered that original clutch equipment, such as the clutch release bearing, is extremely sensitive to installation errors. Known release bearings often include a generally circular collar with spaced apart flat outer and inner flanges extending radially outwardly from the outer surface of the collar. It has been found that these flat flanges allow an end user to incorrectly install a replacement release bearing which causes the clutch system to operate improperly, such as failure to shift, premature wear, excessive pedal effort and system failure.
Proper installation of the clutch bearing in a pocket of the clutch fork is established when both the spring clips and the fork clips are positioned between the outer and inner flanges of the release bearing collar and urged around the collar such that the spring clips frictionally engage the outer flange and the fork clips frictionally engage the inner flange. Improper installation of the release bearing on the fork occurs when the outer flange of the release bearing lies between the fork clips and the spring clips. If the clutch release bearing is not installed properly, the clutch system will not release correctly resulting in premature failure of the release bearing and damage to other parts of the vehicle drive system.
Accordingly, the present inventors have determined that it is desirable to provide a clutch release bearing which prevents placement of the outer flange into an open gap between the spring clips and the fork clips of the clutch fork. The inventors have also found that it is desirable to provide a clutch release bearing configured to permit entry and frictional engagement of the spring clips and the fork clips only between the outer and inner flanges of the clutch bearing, thus ensuring error proof installation of the release bearing in the clutch system.